The optical communication technology is a communication technology that uses light as a carrier to transmit a signal, including an optical fiber communication technology and a visible light communication technology. In the optical fiber communication technology, a laser diode or light-emitting diode is used as a light source, and optical fibers are used as a light transmission medium. In the visible light communication technology, a fluorescent lamp or light-emitting diode is used as a light source, and air is used as a light transmission medium. In both the optical fiber communication technology and the visible light communication technology, a transmitting apparatus needs to superimpose or modulate information on an optical carrier, so as to transmit a modulated optical signal, and a receiving apparatus demodulates the optical signal to obtain information.
In recent years, visible light communication has attracted increasing attention. A visible light communication device includes an optical communication transmitting apparatus used as a transmitting apparatus and an optical communication receiving apparatus used as a receiving apparatus. The visible light communication device modulates information into variation of intensity of an optical carrier, and transmits information by using a flashing light signal. Since the variation of intensity of an optical carrier has a high frequency, human eyes will not even feel light flashing. The visible light communication can use indoor lighting equipment rather than a wireless local area network (LAN) base station to transmit a signal, so that lighting and communication can be achieved at the same time. A communication speed of the visible light communication may reach tens to hundreds of megabytes per second. Uploading or downloading at a high speed can be implemented as long as light irradiation exists. The communication speed will not be affected even when multiple computers work at the same time. The visible light communication technology also features high security, and information leakage cannot occur as long as light is blocked.